I was able to setup everything and Atmos from e.g. Netflix (6 Underground) is working perfectly. 

However, I was not able to get TrueHD working so far. I tried it via Apple TV 4K Using Infuse but it of course transcodes it to Dolby Digital 5.1, same thing for PLEX.

The next thing I will try is to connect via DLNP to my NAS Server. I really don’t know is this a LG, Sonos or PLEX issue?

Anyone else who could stream True HD?

Another question, is there a big difference between Dolby Digital 5.1 and TrueHD?

To get trueHD you need an external source connected to the tv via earc. Apple TV doesn’t support trueHD unfortunately. You’d need a Blu-ray player or something like an nvidia shield.
the internal apps also don’t support TrueHD. 

The difference between them is that trueHD is lossless, so the audio is transmitted as is to the soundbar. 
dolby digital plus is lossy, compressed audio to reduce the bitrate. 
there is a certainly a difference between the codecs, but it might not be enough of a difference for most people to worry about it. 

Ok, so I just added an external USB Drive to my C9 and tried to play it via the internal media player from the TV, but again “audio format not supported”

This is quite disappointing.

Therefore, unless I buy something like a nvidia shield which is supporting trueHD, I will not get it correct?

Or can this be added at a later stage?

BTW: I assume the Arc is supporting TrueHD?

That’s right, you’d need an external player. I’ve not seen any information about LG being able to support TrueHD from its internal apps, I think I recall seeing it being a limitation of WebOS so I wouldn’t hold out hope on support coming. LG are notorious for not supporting their TVs for very long so it would likely be on a later model if at all. 
 

The Arc does support TrueHD yeah, I use an nvidia shield to pass through my media files on Plex and get TrueHD that way. 

So im running the atmos on earc and I have a shield pro (newest model) on another hdmi slot and I play a true HD source on plex (blueray movie or Dolby atmos test file). Somehow the best audio I get is Dolby digital plus 7.1 and plex tell me atmos is not supported on thisdevice. What am I doing wrong to get atmos playing?

Hi all,

I just purchased lg oled bx series with Arc, and i connect it with my sony ubp- x800. The problem is can't playing dolby atmos. Atmos work perfectly fine on netflix.

Any suggestions guys.

Thanks

i picked up one of these PERLESMITH Universal TV Stand for my 55C9 - it has adjustable height and easy assembly. they have a larger version for 65” and an even beefier version for up to 70” TVs.

Could you share a picture how this looks like?

From different viewpoints if possible.

thank you

Hi,

How can you tell if the ARC is playing dolby true hd , as I presume there will be no dolby Atmos badge in the sonos app?

My setup for shield is

ARC sound bar eARC slot to eARC slot HDMI 2 on C9, with shield connected to HDMI 1 on the C9

For shield plex app, pass through and available audio formats set too Auto

sure thing!

Hi guys, new Sonos owner here and I’m having trouble getting Atmos to work consistently.  My ARC + Sub is hooked up to my 2019 LG C9, but I’m not experiencing the same level of success reported by many others.  I can’t seem to find the root cause, so I was hoping for guidance/help.

Here are my results:

Settings: HDMI ARC selected, eARC enabled, and I’ve tried both Passthrough & Auto; firmware: 4.71.25 (before LPCM update I believe).  Also, I did try cycling eARC and passthrough off and then on as suggested earlier.

Internal Apps:

• Dolby Access: reports Dolby Atmos!
• Plex: reports Dolby Atmos!
• Netflix (used 6 Underground but I don’t subscribe to UHD tier): reports  DD+ 5.1
• Prime (used s1:e1 of Jack Ryan): reports DD+ 5.1

Apple TV 4K:

• Plex: reports DD 5.1 (no Atmos)
• Netflix: DD 5.1
• Prime: DD 5.1

Nvidia Shield (2017):

• Plex: reports Dolby Atmos!
• Netflix: DD+ 5.1
• Prime: DD+ 5.1

Am I missing something? Netflix may be a subscription issue, but I have no idea why Plex isn’t working on the ATV (since it’s working fine via the shield and internal app).  I also don’t have an answer for Prime Video since there aren’t additional streaming tiers.  Any thoughts would be greatly appreciated!! I’d also be happy to start a new post if that’s a better option.

@Vyktym, it looks like you're mostly all set. until you subscribe to the UHD tier for netflix you also won't see Atmos. for Prime, try s1, episode 2 of jack ryan. for some reason episode 1 is not in Atmos.

i don't have an ATV4K so not sure of specifics there but everything else appears to be working.

That seems to be tricky.

I have done a lot of tests with my brandnew LG 9C (updated), an Apple TV4, Fire Cube, SKY Q.

I think there is a handshake problem and a problem with the Apple TV4/MAT.

Short Version:

First everything seems to be ok and Atmos worked, Then no Atmos at all. After rebooting everything, Atmos with Netflix worked (TV app, ATV App), amazon and SkyQ also (settings as described at the beginning of this thread),

Apple TV4/Apple TV+ content (See) is also working with Atmos.

But itunes content (1917j worked only for a few minutes, after switching between bitstream and pcm. Then I got only a horrible sound with the German format. English format worked a short time, then only Stereo 2.0 but loud and clear. so I had to switch to Dolby 5.1 in the Apple menu to hear a normal sound (German format),

I don’t understand the difference between Apple TV+ and itunes movie content.

I think there is more than one problem...

I have a similar setup C9 / Apple TV/ Arc

Unfortunately, I updated to the latest Firware Version (04.08.xx) and now everything is kind of screwed up. Now I’m playing around with settings and trying to fix it.

There are so many options which are solving the issue of getting back the speech channels, however the Sonos app is always showing Stereo 2.0.

What is the right setting on my LG c9, not to only get the speech channels back but also proper audioinput how it was before??

In the HDMI ARC Options:

-Do I disable eArc

-Or do I set “Digital sound out” to PCM instead of pass trough

Another option would be to set HDMI Input Audio Format from Bitsteam to PCM

As metioned I want to have it properly fixed, and not just the speech channels back.

Can anyone help here? For now I will continue to use LGs inbuilt apps.

@Ryan S : I would really appreciate if this L-PCM feature will be implemented in a timely manner. I’m really thinking about returning the ARC back and buying it again when it’s not in this “beta” stage anymore. I expect more from a 900 Euro Soundbar.

Not to mention the “Bass” issue that is reported in another thread.

this would seem to be a question to ask LG since its their firmware that introduce this regression in behavior. they might just have you downgrade firmware.

eARC will be needed in general unless LG thinks it will resolve the new firmware bug.

since the Arc won’t understand any multichannel PCM above stereo i’d suggest setting it to Bitstream on the inputs and Auto or Pass Through for the Digital Sound Out. if those settings don’t work for the ATV4K, it really is something LG will need to fix in the short term since the Sonos hasn’t announced any timeline (and probably won’t) on the LPCM feature.

Everything (ATV 4, SkyQ, netflix and Amazon Prime with build in Apps, with my LG C9 newest firmware) is working now.

Settings:

LG: Earc on / pass through / all HDMI inputs on bitstream (Arc using HDMI 2)

SkyQ: output HDMI Dolby DIgital +

Apple TV4: Format Atmos on (if no Atmos for your language you have to select Dolby Digital  to get the whole sound)

Netflix/Amazon Prime working with build in apps descriptions Dolby Atmos (DD+) but you need Netflix premium for Atmos

Any ETA on the fix for the Arc with LG 04.80.03?

First off thanks for the info .

I have the same config on my C9 as you spelled out. Streaming tidal in Atmos works great as does prime, Disney and Netflix.

Trouble I have is with a Sony Blu Ray. I'm playing  The Beatles Abby Road in Dolby Atmos but Blu Ray will not switch from PCM to Atmos. I've tried all troubleshooting on the blu ray and checked it all. 

Even did a system reset on the blu ray audio and then set it based on info from two sources, Sony and LG. 

No luck. Still sounds great but I would really like to see the Blu Ray switch to Atmos.

Any thoughts?

On Apple TV, go to Settings → video and audio → Audio Format

and set ‘change format’ to off. 

you don’t mention which actual Sony BDP model you have so i just looked at the manual for UBP-X800M2, searched for and found Atmos in the troubleshooting section on page 29 where it mentions:

The HD Audio (Dolby Digital Plus, Dolby
TrueHD, DTS-HD High Resolution Audio,
DTS-HD Master Audio, Dolby Atmos*2 and
DTS:X*3) is not output by bitstream.
• Set /BD Secondary Audio] in Audio
Settings] to tOff] (page 24).
• Check that the Sound Bar/AV amplifier
(receiver) is compatible with each HD Audio
format.

this might be an issue if your device is playing out PCM instead of Bitstream. on the LG C9 side, while you have the Sony BDP input active, check that Settings>Sound>Additional Settings>HDMI Input Audio Format for all inputs is set to Bitstream. all of the inputs are listed but you can only change the active input.

Thanks. It's a Sony BDP-S6700. I did check the manual and have set BD Audio mixing to off per my interpretation, and some other sites and forums. 

No AV receiver. Blu Ray to HDMI 3 on LG then HDMI Arc with eArc turned on to Sonos. 

All the HDMI inputs are bitstream. 

Blu Ray is specifically Dolby Atmos so nothing I can see there . 

My assumption of course is that the TV can decode. I do have an AV receiver and could hook it up but again didn't think I needed it

Thanks

sorry, i didn't mean to confuse the issue of the AV receiver - just wanted to include that line since its the full portion of the troubleshooting note. the main point was for disabling any secondary audio that might include formats that aren't dolby (i.e. DTS).

a receiver would just add a new device to the puzzle.

this sounds like a question for sony tech support.

I appreciate the help and I will hit them up.

Have a great weekend

I have the same issue. I tried changing the eArc to off and Digital Sound Out to PCM from Passthrough ( I see Passthrough, Auto and PCM options only) and played Underground 6 and changed those back to Passthrough and eArc to On. Still all my apps are playing only in Dolby Vision and not Atmos

So I have the LG CX 

and use Apple TV 4K and Oppo203 player

Will I get this issue with 5.1 and stereo that I have read on here. I’m amazed that some of these sound issues still exist, would I be best holding off purchasing until Sonos have updated the ARC with this LPCM fix.